Saw Kerf with respect to the insert centerline

dusty · Post by **dusty** » Fri Feb 10, 2012 4:11 pm

I have been toying with the ZCIs and my ZCI Sled this week. Doing so has brought it to my attention that the saw kerf in all of my table inserts is offset to the right by about 3/16"

This does not cause any problem but I wonder why.

Is there a design explanation for this or is it possible that there is a mechanical issue somewhere in my system?

If it is unique to my Mark V, ZCI cut on my Mark V would not fit, without compensation, on another user's Mark V.

Could it be as simple as the rubber bumper on the way tube is now compressed. It is twenty + years old.

If that bumper was 3/32" wider the kerf would come right down the center line.

JPG · Post by **JPG** » Fri Feb 10, 2012 4:34 pm

dusty wrote:I have been toying with the ZCIs and my ZCI Sled this week. Doing so has brought it to my attention that the saw kerf in all of my table inserts is offset to the right by about 3/32"

This does not cause any problem but I wonder why.

Is there a design explanation for this or is it possible that there is a mechanical issue somewhere in my system?

If it is unique to my Mark V, ZCI cut on my Mark V would not fit, without compensation, on another user's Mark V.

Could it be as simple as the rubber bumper on the way tube is now compressed. It is twenty + years old.

If that bumper was 3/32" wider the kerf would come right down the center line.

What does it measure today?

500 spacer = 3/8"

Difference in arbors(500/505...520) = 7/16"

long spacer = 13/16"? Mine is bulging, so measuring it means nothing.

I have not checked, but AIRI, the Mark 5 was not exactly centered!

Gene Howe · Post by **Gene Howe** » Fri Feb 10, 2012 5:58 pm

Mine was not even close to center.
I've always slid it close and used the quill feed.

dusty · Post by **dusty** » Fri Feb 10, 2012 6:22 pm

JPG40504 wrote:What does it measure today?

500 spacer = 3/8"

Difference in arbors(500/505...520) = 7/16"

long spacer = 13/16"? Mine is bulging, so measuring it means nothing.

I have not checked, but AIRI, the Mark 5 was not exactly centered!

Thank you for that reminder. I have been taking the arbors for granted since the only (saw) arbors I have came with the Mark V and the ones I have are all the same.

If we are discussing the same spacer (carriage stop ring (aka rubber bumper) - 516667), we have a significant difference. Mine measures 1 3/8".

dusty · Post by **dusty** » Fri Feb 10, 2012 6:31 pm

Gene Howe wrote:Mine was not even close to center.
I've always slid it close and used the quill feed.

Where it comes to rest is seldom an issue. At least not one of importance. It does bug me, however, that it is so close and yet so far.

I would like to be able to mark a cut line, on the table insert, that could be used for placement of material being cut. In fact, I have often thought about some way to scribe a line on the main table.

I understand that the quill is adjustable but when I am using the table saw I try to always insure that the quill is retracted ALL THE WAY and the carriage is tight against the carriage stop ring.

If it does nothing else, it extends the life of the ZCI.

reible · Post by **reible** » Fri Feb 10, 2012 6:41 pm

Hi,

I'm sure a bunch of things come into play, but to see what I have on my unit I brought in one of my ZCI's to measure.

In this case I'm only showing the measurement of the ZCI with reference to it self. Mine measured just under 3" wide, the rule was placed at an angle to have the top edge adjusted to 1-1/2" to each side. The 0 then falls along the left edge of the kerf.

[ATTACH]16139[/ATTACH]

Getting into the "rest of the story" is a whole can of worms which I have dug into but do not feel up to sharing at this point.

Ed

algale · Post by **algale** » Fri Feb 10, 2012 6:43 pm

dusty wrote:Where it comes to rest is seldom an issue. At least not one of importance. It does bug me, however, that it is so close and yet so far.

I would like to be able to mark a cut line, on the table insert, that could be used for placement of material being cut. In fact, I have often thought about some way to scribe a line on the main table.

I understand that the quill is adjustable but when I am using the table saw I try to always insure that the quill is retracted ALL THE WAY and the carriage is tight against the carriage stop ring.

If it does nothing else, it extends the life of the ZCI.

Are using shopsmith thin kerf blades or standard full kerf blades? Not sure it makes a difference but perhaps. This is why I have concluded my splitter is closer to the right side of the blade (essentially even with right edge of blade but the left edge of blade is slightly beyond the splitter (and the adjustment screw on the upper saw guard is all the way in).

JPG · Post by **JPG** » Fri Feb 10, 2012 7:13 pm

dusty wrote:Thank you for that reminder. I have been taking the arbors for granted since the only (saw) arbors I have came with the Mark V and the ones I have are all the same.

If we are discussing the same spacer (carriage stop ring (aka rubber bumper) - 516667), we have a significant difference. Mine measures 1 3/8".

FWIW I checked the M5(Goldie) and it positions essentially centered on the insert screws.

I overlooked the table carriage side to support post difference. And the support tube trunion offset. All that will change the 'difference'. I do not have a good way to measure all those things.

JPG · Post by **JPG** » Fri Feb 10, 2012 7:20 pm

algale wrote:Are using shopsmith thin kerf blades or standard full kerf blades? Not sure it makes a difference but perhaps. This is why I have concluded my splitter is closer to the right side of the blade (essentially even with right edge of blade but the left edge of blade is slightly beyond the splitter (and the adjustment screw on the upper saw guard is all the way in).

The thickness of the blade base disc will indeed change the center of the kerf relative to the side against the arbor. Thinner blades(and kerf) would be closer to the arbor(the opposite of what Dusty is describing)

robinson46176 · Post by **robinson46176** » Fri Feb 10, 2012 10:47 pm

You need a Mark VII.

On the Mark VII you slide the carriage (and table) over to the headstock until the carriage mounted "inter-latch" rod enters the hole in the headstock. With the inter-latch lock button pulled out it will latch the carriage solidly to the headstock. The rod has 2 lock points on it. The first is for the saw slot at the edge of the table. The second is for the center (regular) saw slot. If the blade is not in the center of the slot you adjust the inter-latch rod using 2 nuts at the right side of the carriage until it is aligned. From that point on it will line up each time unless you change to another kind of arbor or something. If you don't want the rod to latch you just push the lock button in. Cool system actually. With it latched in place you can loosen the headstock and carriage locks and slide the 2 together back and forth on the way tubes and they will stay in the same exact relationship to each other. A good example here would be that you could slide them both over to the left to couple a bandsaw to the headstock for a quick cut then slide both away to uncouple it to return to using the tablesaw function without the bandsaw running and it will still be properly aligned.

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